Burner for flame cultivators



BURNER FOR FLAME CULTIVATORS 3 Sheets-Sheet 1 Filed May 7, 1963 38 F' i M 58 14 53, l I l I .4mm; im:

S8 INVENTOR,

flow/e0 A! #42055 BY DWHQWM ATTORNEY 7 April 13, 1965 H. PARDEE 3,177,922

BURNER FOR FLAME CULTIVATORS Filed May 7, 1963 3 Sheets-Sheet 2 u' & f

U l l I INVENTOR, 00mm; 4 24mg ATTORNEY April 13, 1965 R. H. PARDEE BURNER FOR FLAME CULTIVATORS 3 Sheets-Sheet 3 Filed May '7, 1963 INVENTORI flaw/e0 A #40255 BY 5 MMM ATTORNEY United States Patent This invention relates generally to apparatus for the cultivation of crops of the general character disclosed in United States Letters Patent to McLemore, 2,408,328 issued September 24, 1946. The general theory of flame cultivation is set forth in detail in Patent 2,408,328, and further description is apparently unnecessary.

In theory flame cultivation is practical and highly desirable. However, it is not only important, but imperative that the burners of the apparatus are operating at substantially peak efliciency at all times. The ability of the burner to remain ignited at all times during operation, i.e., a minimum of fblow outs,.reduces shut-down periods and loss of time.

Additionally, since a predetermined amount of heat must be directed toward the plants, Weeds, etc., in relation to the speed of a tractor vehicle moving along a row of crops, an inefliciently operating burner, i.e., insuflicient B.t.u. output, will result in (l) improper weeding, i.e., poor crops, and (2) excessive consumption of fuel.

One principal factor deterring universal and more extensive use of flame cultivators in farming is the inability of a previously known burner to operate consistently over long periods of time whereby a minimum of maintenance and shut-down periods is encountered during flame cultivation.

Many times during operation of known flame cultivators, due to wind conditions (i.e., a following wind) or atmospheric conditions (i.e., heavy atmosphere due to high humidity, etc.) the products of combustion (i.e., carbon monoxide, carbon dioxide, nitrogen, etc.) which do not support combustion, are drawn into the air intake of known conventional burners and cause the burner flame to be extinguished or ineflicient and excessive fuel combustion. When this happens, ineflicient cultivation occurs, possibly requiring more frequent cultivation periods or inconsistent and inefficient cultivation.

In order to obviate some of the problems with respect to inefiicient combustion and the accompanying inconsistent cultivation, independent blowers, compressors or substantially closed fuel systems have been used in the past.

A primary object of the present invention is to provide an improved burner for use on flame cultivators.

A further object of the present invention is to provide an improved flame cultivator burner which draws air to supoprt combustion from an area removed from the burner to eliminate the hazards of poor atmospheric or wind conditions;

Another object of the present invention is to provide a novel flame cultivator burner which utilizes the heat of combustion for eflicient vaporization of the fuel such as liquid propane or the like being used.

A still further object of the present invention is to provide a flame cultivator burner which includes a venturi portion for inspiring a mixture of air and fuel to be etficiently and thoroughly combusted therein.

And yet another object of the present invention is to provide a novel flame cultivator burner which includes a detachable fuel outlet and fuel jet orifice coupling to facilitate maintenance and repair.

A still further object of the present invention is to provide a novel flame cultivator burner including a fuel vaporization chamber in which liquid fuel is substantially impinged onto a wall common to both the vaporization chamber and a combustion chamber at a point sufliciently removed from a vaporized-fuel inlet whereby substangially only fuel vapor is directed to the combustion cham- These together with other and more specific objects will become apparent from a consideration of the following description taken in conjunction with the accompanying drawings forming a part thereof, wherein:

In the drawings:

FIGURE 1 is a rear elevation of a tractor vehicle having a flame cultivation assembly mounted thereon;

FIGURE 2 is a fragmentary top plan view taken substantially on the plane of line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged vertical section taken substantially on the plane of line 3--3 of FIGURE 2 and showing details on one embodiment of the flame cultivator burner of the invention, portions being broken away for the purpose of showing details;

FIGURE 4 is a sectional view taken substantially on the plane of line 44 of FIGURE 3 looking down on top of the burner;

FIGURE 5 is a rear elevation of the flame cultivator burner looking substantially from the plane of line 55 of FIGURE 3;

FIGURE 6 is a view similar to FIGURE 3 showing another embodiment of the flame cultivator burner;

FIGURE 7 is a view taken substantially on the plane of line 7-7 of FIGURE 6, and similar to FIGURE 4; and

FIGURE 8 is a rear elevational view of FIGURE 6, taken on the plane of line 8-8 of FIGURE 6, and similar to FIGURE 5.

Referring to the drawings in detail, and first considering FIGURES 1 and 2, a suitable tractor vehicle is indicated generally at 10 and will be of the character which will have an adjustable speed control to permit it to move between a row of crops at a uniform rate of travel.

Suitably mounted on the rear of the tractor 10 at 12 is a flame cultivator assembly indicated generally at 14. The tractor and mounting for the flame cultivator, as mentioned above, are of any suitable character, and it will be recognized by those skilled in the art that the flame cultivator assembly could be mounted on the side or front of the tractor vehicle in the manner shown for example in the US. Letters Patent to McLemore, 2,408,328. Additionally, the basic principles of flame cultivation are set forth in the patent to McLemore, mentioned above, and thus a detailed explanation thereof is apparently unnecessary.

The flame cultivator assembly 14 includes a pressurized fuel supply tank 16 suitably mounted on the tractor vehicle 10. The tank 16 will generally contain liquid propane (LP) or the like and will supply fuel through a conduit 18 to a manifold type conduit 20 which has connected thereto a plurality of branch lines 22 for fur nishing fuel to the different burner assemblies indicated generally at 24.

The tractor vehicle includes a transverse support or tool bar 26 upon which is mounted suitably spaced fittings 28 from which depend vertically adjustable support rods 30 having lower skids or support shoes 32. The rods 39 have extending from a fitting 34 opposed substantially horizontal rods 36 (only one shown) which have extending therefrom lateral support rods 38 and 40 which are suitably mounted thereon a burner 24; the mounting being adjacent the rear lower surface of the burners. i

The burners are disposed in staggered pairs; see FIG- URE 2, however, this is not part of the present invention. It will be clearly apparent. from FIGURES 3 and 6, note serrated mounting brackets 42 and 42' on burners 24 and 24', respectively, that the optimum angle Patented Apr. 13, 1965 1 If the tractor vehicle moves at a uniform rate of speed,

and various adjustments have been made as to the burner angle, height, etc., it might be assumed that efiicient flame cultivation willbe accomplished. However, problems of improper combustion due to excessive products of combustion adjacent the burner air inlet, adverse wind conditions, improper fuel vaporization, contaminated burners, etc., are factors which must be substantially eliminated or reduced in order to obtain uniform and consistent cultivation.

The present invention involves the improved burner assemblies indicated generally at'24 and'24, and similar primed reference numerals will be used to describe the later mentioned embodiment to facilitate the identification of similarly functioning portions thereof.

The burner of the present invention lends itself to being constructed from a suitable sheet metal or the like.

Referring to FIGURES 3-5, the burner assembly 24 comprises an elongated hollow body 44 including forwardly tapered upper and lower walls 46 and 48; the serrated mounting bracket 42 being suitably secured beneath and adjacent a transverse rear wall 50. The body 44 includes pairs of front and rear side wall portions 52 and 54, the pairs of side wall portions converging intermediately of the body 44 and forming an intermediate venturi throat portion 56 for drawing a mixture of fresh air into the burner in order to sustain efficient combustion therein.

The portion of the body 44 bounded by portions 52, and forwardly of the venturi portion 56, may be generally described as the combustion chamber area, and as will be observed in FIGURE 4 flares outwardly from the venturi throat portion 56. The portion bounded by portion 54, rearwardly of the venturi portion, may be generally described as the fuel and air mixing chamber.

Communicating with the fuel and air mixing chamber within the body 40 and adjacent the rear Wall 50 is a vertically extending air intake tube 58 which is of a substantial cross-section. The upper end of tube 59 terminates well above the burner 24 and thus during conditions where smoke accumulates adjacent the groundbeing cultivated or. during adverse Wind conditions, essentially fresh, combustion supporting air will be drawn into the fuel and air mixing chamber.

Fixed to the upper surface of the wall 46 of the burner is ahousing 60, cylindrical, if preferred, and forming above the combustion chamber a fuel vaporizing chamber 62. The burner will be ignited in any suitable manner, for example, by an electrical'igniter (not shown) and the heat of combustion will vaporize liquid fuel delivered into chamber 62.

Fixed to one side of the housing 60, by welding, for example, is one end of an L-shaped fuel inlet conduit 64 which is connected at 66 by a suitable coupling to one of the branch lines 22. The conduit 66 includes a portion 68 within the housing 69 which terminates in a downwardly bent terminal baffie plate portion '70 overlying the portion 68 and forming a downwardly opening slot 72. The slot directs liquid fuel intermediately of :he upper surface of wall 46 subject to the extreme heat n the underlying combustion chamber. In this manner, iquid fuel is substantially vaporized.

Fixed to the wall of the housing 6!) is a vaporized :uel outlet tube 74 which includes an inlet 76 substanially spaced from slot ,72 to essentially insure that liquid 'uel does not pass therethrough. In the event liquid 'uel should accumulate in the bottom of housing 60, he inlet 76 is spaced thereabove to aid to prevent liquid uel from moving therein.

The outlet tube 74 extends through the air inlet tube i8 and causes a turbulence to the incoming fresh air to .id in good fuel and air mixing rearwardly of the venturi IOIlZlOIl 56. The rear end of tube 74 projects beyond wall 50 and is threaded at 78 to removably accommodate thereon a combined fuel-strainer and burner jet assembly indicated generally at 80.

The assembly 80 comprises an L-shaped coupling 82 including an internally threaded, captive sleeve 84 on one end. The sleeve 84 includes an internal screen seat 86 which receives thereon the flanged end 88 of an elongated, conical vaporized fuel straining screen 90. The coupling 82 includes a threaded nipple portion 92 to which. is secured an elbow 94 receiving therein an elongated jet mounting tube 96.

The wall 56 of body 46 includes a transverse support sleeve 98 in substantial alignment with the longitudinal axis of body 46- and removably receiving sleeve 96 therein. The terminal end of sleeve 96-threadedly supports thereon a jet or orifice element 160 which. can be readily lreilzmoved, replaced 'or cleaned by a piece of wire or the The entire assembly 89 can be removed as a unit by loosening the captive sleeve 84, and it will be apparent that the screen can be readily removed and replaced, and access will be had to the orifice element 169. The assembly 80 can be removed and replaced as a unit, and thus a minimum loss of time is involved for this maintenance. 7

Once the burner has ignited, liquid fuel is readily vaporized in chamber 62, fresh, uncontaminated air is drawn into the fuel and air mixing chamber, and the air drawn into the body 46 will impinge on tubes 74 and 96 to cause turbulence and mixing of fuel vapor emitted from the orifice element.

Referring to FIGURES 68, another slightly modified burner assembly is indicated generallyat 24. The burner assembly 24' includes, a body portion 44' including an upper wall 46 and lower wall 48. A rear wall 50' has mounted thereon a fuel strainer and burner jet assembly 80' essentially the same as assembly 80 previously described in detail.

The body 44" is formed with an intermediate venturi portion 56' of a slightly different configuration from the comparable portion 56 of FIGURES 3-5, but functioning in the same manner. The body 44' communicates with an air intake tube 58 which permits uncontaminated air to be drawn therein.

The body 44' has formed thereon a housing 60 which corresponds to and covers essentially the entire combustion chamber of the burner and has a bottom wall common therewith to form a fuel vaporization chamber 62'. A fuel inlet conduit 64' communicates liquid fuel to the chamber 62' by means of an aperture 63' in the upper wall of housing 60'. Liquid fuel impinges on the bottom of the chamber 62' substantially at the rear thereof, and a vaporized fuel outlet tube 74' extends into the vaporization chamber. The rear end of tube 74' receives a screen 90' of the assembly 80', and the forward or inlet end 76'.terminates adjacent the forward end of chamber 62. Thus liquid fuel impinging and entering into therear of chamber 62 will be substantially, if not com-- pletely, vaporized as it leaves tube inlet 76.

All of the advantages and benefits afforded by the: assembly 24 are present in assembly 24. The essential difference between these embodiments resides in the difierently conformed liquid fuel vaporization chambersv which function in a generally similar manner.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown inthe drawings and described in the specification with respect to the exemplary embodiments,

but only as indicated in the appended claims.

from said open forward end a combustion chamber area, intermediate venturi portion and fuel-and-air mixing chamber, an air intake tube extending vertically from said body member at the immediate rear of said body member and communicating directly with the interior of said fuel-and-air mixing chamber rearwardly of said venturi portion, said air intaketube terminating at the upper end substantially above the body member to provide a relatively uncontaminated supply of combustion air which will be directly inspired into the rear portion of said fuel-and-air chamber by said venturi portion, a vaporization chamber overlying the upper surface of said combustion chamber area at the upper surface of said body member and subject to the heat generated therein, a fuel inlet tube directly extending to and communicating with said vaporization chamber for directing liquid fuel thereto, a vaporized-fuel outlet tube communicating with the rear of said vaporization chamber and extending transversely through the lower end of said air intake tube and terminating exteriorly at the rear of said body member, and a coupling assembly including a fuel orifice connected to said vaporized-fuel outlet tube, said fuel orifice extending directl into said fuel-and-air mixing chamber at the rear of said body member rearwardly of said 'venturi portion and in intersecting relation to the lower'end of said air intake tube, whereby air directed onto said transverse vaporized-fuel outlet tube and fuel orifice causes turbulence and complete mixing of said vaporized fuel and air.

2. The structure of claim 1 in which said coupling assembly includes an integral screen extending into the rear end of said fuel outlet tube for protecting said fuel orifice from contamination.

3. The structure of claim 1 in which said body member includes a support sleeve on the closed end of said body member in alignment with the center of said venturi portion, said fuel orifice comprising an elongated tube removably supported in said sleeve and including a 5. The structure of claim 4 in which said fuel inlet tube includes an outlet directed toward the upper surface of said bottom wall, said fuel outlet tube having an inlet disposed in spaced relation from said inlet tube outlet.

6. The structure of claim 5 in which said fuel inlet tube comprises a bafl'le portion disposed in spaced overlying relationship with respect to the open end of said fuel inlet tube and forming a downwardly directed slot therewith.

7. The structure of claim 5 in which said fuel inlet tube terminates in an open and directed toward the forward end of said vaporization chamber.

8. The structure of claim 7 in which said vaporization chamber overlies and extends on opposite sides of said venturi portion and terminates substantially at the open end of said body member.

References Cited in the file of this patent UNITED STATES PATENTS 714,722 Macleod Dec. 2, 1902 989,745 Wissinger et al.' Apr. 18, 1911 1,019,640 Hennessy Mar. 5, 1912 1,137,148 Lambert Apr. 27, 1915 1,323,922 Smith Dec. 2, 1919 2,601,895 Garretson et al July 1, 1952 2,839,047 Davison et a1 June 17, 1958 FOREIGN PATENTS 1,194,255 France May 4, 1959 JAMES W. \VESTHAVER, Primary Examiner. 

1. A BURNER ASSEMBLY FOR USE IN A FLAME CULTIVATOR COMPRISING A HOLLOW BODY MEMBER OPEN AT A FORWARD END, CLOSED AT THE OPPOSITE REAR END AND INCLUDING IN ORDER FROM SAID OPEN FORWARD END A COMBUSTION CHAMBER AREA, INTERMEDIATE VENTURI PORTION AND FUEL-AND-AIR MIXING CHAMBER, AN AIR INTAKE TUBE EXTENDING VERTICALLY FROM SAID BODY MEMBER AT THE IMMEDIATE REAR OF SAID BODY MEMBER AND COMMUNICATING DIRECTLY WITH THE INTERIOR OF SAID FUEL-AND-AIR MIXING CHAMBER REARWARDLY OF SAID VENTURI PORTION, SAID AIR INTAKE TUBE TERMINATING AT THE UPPER END SUBSTANTIALLY ABOVE THE BODY MEMBER TO PROVIDE A RELATIVELY UNCONTAMINATED SUPPLY OF COMBUSTION AIR WHICH WILL BE DIRECTLY INSPIRED INTO THE REAR PORTION OF SAID FUEL-AND-AIR CHAMBER BY SAID VENTURI PORTION, A VAPORIZATION CHAMBER OVERLYING THE UPPER SURFACE OF SAID COMBUSTION CHAMBER AREA ATH THE UPPER SURFACE OF SAID BODY MEMBER AND SUBJECT TO THE HEAT GENERATED THEREIN, A FUEL INLET TUBE DIRECTLY EXTENDING TO AND COMMUNICATING WITH SAID VAPORIZATION CHAMBER FOR DIRECTING LIQUID FUEL THERETO, A VAPORIZED-FUEL OUTLET TUBE COMMUNICATING WITH THE REAR OF SAID VAPORIZATION CHAMBER AND EXTENDING TRANSVERSELY THROUGH THE LOWER END OF SAID AIR INTAKE TUBE AND TERMINATING EXTERIORLY AT THE REAR OF SAID BODY MEMBER, AND A COUPLING ASSEMBLY INCLUDING A FUEL ORIFICE CONNECTED TO SAID VAPORIZED-FUEL OUTLET TUBE, SAID FUEL ORIFICE EXTENDING DIRECTLY INTO SAID FUEL-AND-AIR MIXING CHAMBER AT THE REAR OF SAID BODY MEMBER REARWARDLY OF SAID VENTURI PORTION AND IN INTERSECTING RELATION OF THE LOWER END OF SAID AIR INTAKE TUBE, WHEREBY AIR DIRECTED ONTO SAID TRANSVERSE VAPORIZED-FUEL OUTLET TUBE AND FUEL ORIFICE CAUSES TURBULENCE AND COMPLETE MIXING OF SAID VAPORIZED FUEL AND AIR. 